Photoflash lamp

ABSTRACT

A flash lamp containing oxygen under pressure and also a pyrogenic ignitor activatable by percussive force mechanically applied externally while the lamp envelope remains intact and pressure therein maintained; the disclosure including a cubical holder for mounting a plurality of the flash lamps for successive percussive actuation.

United States Patent 3.315.070 4/1967 Pfefierle.... 3,439,992 4/1969 Shaffer etal.. 3,508,478 4/l970 Brooks 3,511,586 5/1970 Kopelman et 3,514,243 5/1970 Hay et al,......... 3,517,182 6/1970 Brooks et al.. 3,537,367 11/1970 Van Duser.................... 3,537,805 11/1970 Michatek [72] lnventor [73] Assignee FOREIGN PATENTS 7/1935 Great Britain Primary Examiner- Edward J. Michael Attorney- Howard P. King [54] PHOTOFLASH LAMP 3 Claims, 5 Drawing Figs. 431,953

[52] 11.8. CI....... 431/93, 240/ 1.3 [51] Int. FZlk 5/02 [50] Field of 431/92-96 ABSTRACT: A flash lamp containing oxygen under pressure 56 and also a pyrogenic ignitor activatable by percussive force mechanically applied externally while the lamp envelope kelerenmCited UNITED STATES PATENTS 2,024,225 12/1935 remains intact and pressure therein maintained; the disclosure including a cubical holder for mounting a plurality of the flash lamps for successive percussive actuation.

2,263,179 ll/l94l Lockwood...............

PATENTEDNUV 30 I971 SHEET 1 BF 3 Karl Herrmann INVENTOR ATTORNEY PATENTEUNDV 30 I8?! SHEET 2 [IF 3 FIG.2

II If Karl Herrrnann INVENTOR ATTORNEY PATENTEnunv 30 men SHEET 3 OF 3 13 Karl Herrmann INVENTOFL BY I m ATTORNEY PHOTOFLASI-I LAMP THE PROBLEM Commonly available flash lamps in use today, are equipped with inlead electrically conductive wires to which electric current is supplied by external batteries which, when switched into circuit, results in generation of enough heat within the flashable material in the lamp to ignite the same and produce the desired flash. inadequacy of the current supply, usually due to weak or spent batteries, often results in failure of the lamp to' flash, and the picture fails to materialize.

Efforts have been made to activate the flashable material by mechanical ignition of a pyrogenic substance associated with the flash material directly within the bulb or the envelope. For instance, one such proposal has employed a flash lamp wherein ignition means is carried by the wall of the lamp envelope. There the ignition is effected by an externally located needle used to penetrate the envelope and instigate fireproducing sparking in penetration through the pyrogenic layer in the lamp. An oxygen content under a pressure in such a pierced lamp cannot be used in view of the consequent escape of pressurized oxygen immediately upon a piercing of the envelope. Aside from the fire hazard involved, destruction of the lamp seal presents the drawback of immediate reduction of gas pressure, and thereupon, due to the indefinite lowered pressure both before and during combustion, the process is uncontrollable and adversely affects the intensity of the flash.

Modifications of the above-related piercing method have been proposed, such for instance as attempting to immediately reseal the envelope. Another proposal has been to utilize a breakable glass tubulation in an evacuated envelope containing a hypergolic or pyrophoric material, that is, a material which ignites spontaneously when contacted by air. The theory of such a device is that upon breakage of the tubulation, air is sucked therethrough and ignites the hypergolic material with the fire thereof communicating to the flashing material in the lamp. This, like the other mentioned propositions have proved to be impractical and definitely unsatisfac- Primarily the invention is directed to provision of improved and infallible flash lamp ignitable without resort to electrical" circuits or batteries.

Also in its broad aspect, the invention proposes an improved mechanically ignitable means to instigate the flash.

More specifically, the invention provides an oxygen-filled envelope and a mechanically activated ignitor operable therein with the envelope maintaining the internal pressure by remaining sealed.

In greater detail, an object of the invention is to provide a constantly sealed flash lamp containing flashable material and oxygen under pressure together with a pyrogenic ignitor subject to mechanical incitation while still sealed within the envelope.

Corollary to the foregoing object, it is a purpose of the invention to provide for external actuation of the mechanical instigation of the ignitor.

Furthermore, an object of the invention is to provide a mechanically started flash lamp which may be ignited easily by such mechanical means, and which is adapted to be inserted without difficulty into a multiple holder and the holder conveniently mounted on a camera and flashing obtained without any vibration which would be adversely effective on the picture.

Other objects, advantages and novel features of construction will become evident to persons skilled in the art to which the invention appertains, both by inference from the context and by direct recitation, as the description proceeds.

THE DRAWINGS Referring to the accompanying drawings, in which like reference characters apply with respect to the same parts in the several views;

FIG. 1 is a longitudinal section of a flash lamp constructed in accordance with the invention;

FIG. 2 is an underneath view of a cubical throwaway pack or holder containing four of the flash lamps;

FIG. 3 is a side elevation of said pack or holder;

FIG. 4 is a partial cross section through the base of said packor holder; and

FIG. 5 is a perspective view of the pack or holder, but with the cubical container portion and the base portion shown in a separated condition one from the other for better illustrating the construction of those parts.

DESCRIPTION In the specific embodiment of the invention illustrated in the drawings, and referring initially to FIG. 1, the structure shown provides a transparent closed tubular envelope 1, which is filled with finely distributed combustible flash material 2, such as shredded zirconium foil, and with oxygen under pressure, the extent of which has been satisfactorily chosen as seven atmospheres.

At what appears in the drawing as the bottom end of the envelope, situated longitudinally with respect thereto, is a slender metallic tube 3 such as copper or an alloy, of which iron-nickel is an example. A criterion for the metal utilized is that it must be sufficiently ductile, malleable or flexible to permit crushing or collapse of the tube under a moderate percussive blow without rupturing the metal. The walls of said tube are made very thin, comparative to that of thick paper, for which reason they may be described as paper thin.

The upper end of said tube 3 opens into the interior chamber of the envelope 1. The material of which the envelope is composed, which may be glass, is sealed around the outer circumferential surface of the upper end portion of said tube. The lower end portion of the tube is exterior of the envelope, projecting therebelow for example a distance of 4 millimeters. The bottom extremity 4 of the protruding end portion of the tube 3 is appropriately sealed as by cold press welding and soldering.

The tube 3 is filled with a shock-sensitive pyrogenic substance 5, that is to say, a substance which readily fires when subjected to percussive pressure such as will occur when denting the tube at the part thereof containing said substance 5.

Said pyrogenic substance 5 preferably does not extend further up into the metallic tube 3 than vicinity of the level of the sealing of the envelope therearound. This restriction of the pyrogenic ignitor substance extending at the most only up to the sealing, is desirable for the reason that, if the tube is filled all the way with the ignition substance, the likelihood then exists that the pressure wave created upon ignition will cause breakage of the glass, thereby releasing the oxygen pressure.

As examples of appropriate materials for satisfactory use as the ignitor, mention may be made of salts of fulminic acid as well as to a mixture of red phosphorus, potassium chlorate and a binder.

For assurance of infallible activation of the flashing material, a primer is preferably employed in conjunction with the aforementioned ignitor substance. This primer may consist of a quickly responsive substance to activation consequential upon functioning of the ignitor substance. An acceptable primer material comprises, for example, for the most part zirconium powder with an oxidation component, such as potassium chlorate and a binder. If desired, this primer may be mixed with the shock-sensitive material ignition means and included therewith in the metallic tube 3. The primer functions under activation by the shock-sensitive means to throw off little redhot particles which will penetrate amidst the lamp filling and cause it to flash.

On the other hand, the primer may be introduced as a wad 7 at the inlet or point of entry of the metallic tube 3 into the lamp chamber. Percussive instigation of firing of the shocksensitive material produces a hot pressure wave which activates the primer and red-hot particles therefrom cause the lamp fill to flash.

In the course of manufacture of the lamp, after the several mentioned materials have been introduced into the metallic tube 3 and bulb 1, the lamp is exhausted through a tubulation 6 provided at its upper end, then refilled with oxygen under pressure and the tubulation appropriately sealed. Thus constructed, the lamp is ready for use.

In use, flashing is accomplished by giving the protruding metallic tube 3 a sharp blow from opposite sides by suitable mechanical means, such as by jawlike hammers indicated herein by arrows 18.

The disclosure includes a cubical 19 for mounting a plurality of the novel flash lamps of FIG. 1 for successive percussive actuation, such a holder being shown in FIGS. 2-5 herein. Cubical holders in general for mounting on cameras are known in the prior art, and in conjunction therewith mechanism has been provided for indexing or giving a step-by-step rotation to the holder between successive picture-taking operations of the camera. The herein illustrated holder is adapted for similarly being advanced as taught by the prior art, but has a construction for protectively receiving the metallic tubes and positioning them successively in place for denting to activate the ignitor material and produce the desired flash.

Such a device as here shown has a base plate 8 receiving the lower ends of four photoflash lamps 9 and a reflector unit constituting four individual reflectors 10, as well as a cover cap 11. The upper exhaust tubulation 6 engages in a recess provided in the respective reflectors. The downwardly projecting little metallic tube 3 passes through a respective hole 8a therefor in the base plate 8 of the holder. Said base plate 8 is substantially square and constitutes the bottom of the cubical portion of the holder.

' Projecting from the under face of said base plate 8 in fixed relation thereto, is a generally cylindrical extension 12 axially coincident with the center of the square base plate and providing a downwardly open hollow interior 15. For better understanding, the holder of FIG. has been arbitrarily separated into two sections with the said cylindrical extension spaced downwardly away from the square base plate 8, but in practice no such separation exists.

The bottoms of the lamp bulbs are accommodated in saucerlike recesses 17 in the base plate proximate to and midway of the length of the side edges thereof. Holes 8a in the base plate and continuing through the extension are centered at the bottom of said saucerlike recesses and permit passage of the metallic tube 3 of the lamp when the lamp seats in said recess. With the lamps thus located, said tubes 3 are adjacent to and parallel to the outer surface of the sidewall of the extension 12, but do not project below the bottom plane of the extension. The outer wall surface of the extension is deflected radially inwardly at the location of each hole 8a so that the tube 3 is at the outside of the periphery of the extension within recess 13 created by said deflection. Radially outwardly from location of the holes 8a the header portion of the extension provides, at its periphery, depending lugs or guards 14.

The metallic tube 3 of each lamp occupies a position directly behind a respective lug 14 and is protected thereby from being contacted on a direct radial path approaching from the outside of the extension 12, but can be reached by approach around the sides of the lug by way of recess 13. Jawlike hammers (not shown) represented by arrows 18 provided on the camera, are arranged and adapted to enter the individual recess that is most forward with respect to the camera, making arcuate path in the recess 13 to strike the tube 3 on opposite sides. It will be recognized from the bottom plan of FIG. 2, that the metallic tube 3 below where protruding from hole 8a has clearance between the wall of the recess 13 and proximate face of lug 14. It may also be mentioned that the inner wall surface defining the periphery of the hollow 15 in extension 12, has radially inwardly directed wedge-shaped protuberances or dogs 16 which function in conjunction with the camera indexing mechanism for rotational placement and arrest of the holder 19 in accordance with prevailing practice in the art.

The simplicity of the holder enables it to be made with extreme economy, for instance from plastic; it may be loaded with flash lamps before delivery to a customer; and may be thrown away after the lamps have been used. In the manufacturing process of photoflash lamps according to the invention, savings are effected in consequence of the omission of hitherto generally used very thin ignition wires which present the problem of installation difficulty inclusive of connection with the external contacts required therefor. In use there also may be failure of perfecting circuit connections from those contacts to the battery in addition to likelihood of failure of the battery to produce adequate current. Furthermore, the very sensitive ignition system with its very fine tungsten wire may be impaired through the shredded foil. On the other hand, according to the present invention, the ignitor produces a whirling of the gas and diffusion of the projected sparks evolved into the foil, attaining peak performance without having to depend upon a battery being in good condition. This advantageous characteristic is a boon to amateurs and other users of cheap equipment who have had no other choice than battery-operated flash attachments.

I claim:

1. A photoflash lamp in combination with a holder therefor, said lamp comprising a transparent bulb containing a flashable filling with combustion supporting means, said lamp being provided coaxially thereof with ignition means activatable mechanically, characterized by provision of a little metallic tube one inner end portion whereof is sealed coaxially in and opens into the bulb and the other outer end portion projects coaxially externally of the bulb, said tube being closed at its outer extremity, both of said portions having lengths many times greater than the diameter of said little metallic tube, said outer portion only of said tube containing a shock-sensitive initial ignition material at the most extending only up to the level of the seal, whereby the inner end portion of the tube where sealed to the bulb is devoid of said ignition material, said tube being deformable for conveying an externally applied percussive blow to said ignition material, and said holder being symmetric about a center and adapted to carry a plurality of the lamps for successive flashing, said holder providing a base plate with the lamps seated thereon at fixed locations in circular disposition concentric to said base plate and a cylindrical extension projecting below the base plate concentric to and integral therewith, said base plat having holes also in circular disposition and at less distance from the axis of said cylindrical extension than the radius to the outer circumference of said cylindrical extension and with each said hole centrally disposed at said location of the respective lamp thereat for reception of said little metallic tube of the lamp and thereby center each lamp at its respective location all at the same radial distance from said circumference, and wherein said cylindrical extension has recesses, medial parts whereof underlie said holes, each of said recesses extending in opposite directions from said hole laterally of the extension radius thereat whereby ends of each recess open at the periphery of said cylindrical extension and with each recess receiving a little metallic tube of the lamp therein medially between the recess ends of said extension having a lug at each said recess located radially outwardly from said tube and with the respective recess ends opening outwardly of the cylindrical extension at both sides of the lug thereat.

2. A combination in accordance with claim 1, wherein said cylindrical extension is axially hollow and the wall of said hollow has wedgelike protuberances projecting radially inwardly of the hollow with the wedge sloping areas of said protuberances facing upward and situated at a distance from opposite ends of said hollow.

3. A combination in accordance with claim 1, wherein said cylindrical extension has recesses opening at its ends at the periphery of said extension with each recess receiving a lamp tube therein medially between said ends of the recess, and said extension having a lug at each said recess, radially outwardly of the extension midway of the length of said recess and opposite to the lamp tube, and each recess opening outwardly of the extension at both sides of the lug then-eat.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,624,824 Dated November 30, 1971 In e t Karl Herrmann It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 11, after "cubical" insert holder Column 4, line 45, "plat" should read plate line 60, "ends of" should read ends, and

Signed and sealed this 14th day of November 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents II 5 GIWI'HNMENY PRINTING OFFICE I969 II um-1H 

1. A photoflash lamp in combination with a holder therefor, said lamp comprising a transparent bulb containing a flashable filling with combustion supporting means, said lamp being provided coaxially thereof with ignition means activatable mechanically, characterized by provision of a little metallic tube one inner end portion whereof is sealed coaxially in and opens into the bulb and the other outer end portion projects coaxially externally of the bulb, said tube being closed at its outer extremity, both of said portions having lengths many times greater than the diameter of said little metallic tube, said outer portion only of said tube containing a shock-sensitive initial ignition material at the most extending only up to the level of the seal, whereby the inner end portion of the tube where sealed to the bulb is devoid of said ignition material, said tube being deformable for conveying an externally applied percussive blow to said ignition material, and said holder being symmetric about a center and adapted to carry a plurality of the lamps for successive flashing, said holder providing a base plate with the lamps seated thereon at fixed locations in circular disposition concentric to said base plate and a cylindrical extension projecting below the base plate concentric to and integral therewith, said base plat having holes also in circular disposition and at less distance from the axis of said cylindrical extension than the radius to the outer circumference of said cylindrical extension and with each said hole Centrally disposed at said location of the respective lamp thereat for reception of said little metallic tube of the lamp and thereby center each lamp at its respective location all at the same radial distance from said circumference, and wherein said cylindrical extension has recesses, medial parts whereof underlie said holes, each of said recesses extending in opposite directions from said hole laterally of the extension radius thereat whereby ends of each recess open at the periphery of said cylindrical extension and with each recess receiving a little metallic tube of the lamp therein medially between the recess ends of said extension having a lug at each said recess located radially outwardly from said tube and with the respective recess ends opening outwardly of the cylindrical extension at both sides of the lug thereat.
 2. A combination in accordance with claim 1, wherein said cylindrical extension is axially hollow and the wall of said hollow has wedgelike protuberances projecting radially inwardly of the hollow with the wedge sloping areas of said protuberances facing upward and situated at a distance from opposite ends of said hollow.
 3. A combination in accordance with claim 1, wherein said cylindrical extension has recesses opening at its ends at the periphery of said extension with each recess receiving a lamp tube therein medially between said ends of the recess, and said extension having a lug at each said recess, radially outwardly of the extension midway of the length of said recess and opposite to the lamp tube, and each recess opening outwardly of the extension at both sides of the lug thereat. 